The color of damage numbers matters. White=normal. Yellow=Weakness. Grey=Resistant. So the type of weapon you are using can have a significant impact.
For instance you can spend all day shooting bonemass with regular arrows because he's resistant to piercing....or you can spend under 3 minutes giving him a beat down with a iron mace since he's weak to blunt damage.
The games gives you enough information to figure everything out, it just doesn't handhold and spell everything out in specific detail.
Like for taming, a stone tells you you can tame boars, and only certain animals say "wild, hungry" when you target them, another hint.